Process Flow Diagrams (PFDs) are graphic representations of process models. Diagrams typically contain a plurality of processing stages, or nodes, with a plurality of interconnecting lines. These interconnecting lines, also called process streams, represent physical transfer of material between interconnected nodes. Linear Programming (L.P.) models for refining, chemical and petrochemical plants are known in the industry and have in the past been used to optimize process plant economics. An L.P. model is created by running an L.P. optimizer on the process model.
PFDs have typically been created manually or with a Computer Aided Design (CAD) or Drafting program. This required the user to determine the layout of every processing node and the routing of every process stream in the PFD.
Once a PFD has been generated, subsequent modifications to the process model including hiding of zero flow streams, hiding of selected processing nodes, hiding of process streams, forming and modifying groups of processing nodes, and optimizing the process model, required extensive manual modification to the original PFD. The difficulty and tedium of this task of creating and modifying PFDs has virtually precluded the construction of PFDs from L.P. models in the Process Industries.